1. Field of the Invention
This invention relates to crop harvesting headers having draper or conveyor sections movable in lateral directions for either left, right, or center crop delivery through a discharge opening and onto the ground in a windrow.
2. Description of the Prior Art
Windrowing headers equipped with conveyors in the form of drapers are widely used in certain regions of the world. Typically, draper windrowers are provided with at least two independent draper sections which cooperate to transversely convey the severed crop materials toward an opening for discharging the materials on the ground to form a windrow during advancement of the machine.
In some instances, the draper sections of windrowing headers are shiftable in directions laterally of the path of travel of the machine to cooperating positions such that the discharge opening is located either adjacent the right or left side of the machine or alternately is positioned near the center of the header. Hydraulic cylinders are utilized to transversely shift the draper sections during the harvesting operation so that the discharged crop materials are laid down in a windrow beside a previously formed windrow in order that the harvesting machine subsequently processing the crop materials will have a larger volume of material to pick up along each pass across the field.
A number of factors are known to affect crop yield and consequently the volume of severed crop materials per linear foot of windrow may vary from year to year. In instances where crop yield is relatively heavy, the discharge opening normally provided by conventional draper harvesters is of a width for satisfactorily establishing a well-formed windrow wherein the crop materials are substantially interlaced for resisting dispersement by wind, and wherein the windrow presents an elongated, central apex extending the length of the windrow for preventing collection of snow which might otherwise impair the quality of the crop materials.
There are times, however, when the standing crop density is relatively light such as after growing periods when rainfall has been inadequate. The less dense windrow formed by the above-mentioned opening of the harvester under such conditions is not well formed by comparison and may present an elongated depression along the center of the windrow which is susceptible to collection of snow and ice. Moreover, the crop materials under these circumstances may be insufficently interlaced and as a result may be unable to adequately resist scattering due to the influence of driving winds.
In the past, certain manufacturers have attempted to alleviate the above-noted problems by providing an extra length of conveyor fabric (such as canvas or synthetic rubber) which may be added to the existing draper sections to reduce the transverse width of the discharge opening. To extend the conveyor sections, the user attempting such a conversion would first disassemble the draper and add the additional fabric section, and then extend the carriage frame by adding additional members in order to stretch the draper to the proper transverse width. However, such a process must be normally repeated for each draper section and often entails a laborsome task extending over a number of hours.
Obviously, it would be highly desirable to reduce the time necessary for varying the discharge opening width of conventional harvesters. In many cases, the header may be put to use each season in a number of different fields, and a simplified apparatus for adjusting the discharge width would certainly be desirable since crop conditions may vary from field to field.